MARS-a multilevel full-chip gridless routing system

This paper presents MARS, a novel multilevel full-chip gridless routing system. The multilevel framework with recursive coarsening and refinement allows for scaling of our gridless routing system to very large designs. The downward pass of recursive coarsening builds the representations of routing regions at different levels while the upward pass of iterative refinement allows a gradually improved solution. We introduced a number of efficient techniques in the multilevel routing scheme, including resource reservation, graph-based Steiner tree heuristic and history-based iterative refinement. We compared our multilevel framework with a recently published three-level routing flow . Experimental results show that MARS helps to improve the completion rate by over 10%, and the runtime by 11.7/spl times/.